Speed-changing cam-driving mechanism



March 2 1926.

L, K. BRAREN SPEED CHANGING CAN DRIVING MECHANISM 2 Sheets-Sheet 1Original ma Nov. 28, 1922 L. K. BRAREN SPEED CHANGING CAM DRIVINGMECHANISM Original Filed Nov. 29, 1922 2 Shasta-Sheet 2 4 2 Aan ra a5/01? Patented Mar. 2, 1926.

UNITED STATES .PYATENTX OFFICE.

LORENZ KONBAI) isnannn, or MUNICH, GERMANY, nssrenon woman man FRIED-mcrr DECKEL, FABRIK 1 rim rmizIsIoNsMEoHANIK UND MASOHIN'ENBAU, on

mmxcn, GERMANY..-

SPEED-GHANGING CAM-DRIVING MECHANISM,

Original application filed November 28, 1922, Serial No. 603,871.Divided and v 4, 1924. Serial No. 717,713.

To all whom it may concern:

Be it known that I, LORENZ KONRAD BRA- REN, a citizen of Germany,residing at 22 Porten Strasse, Munich, Bavaria, Germany,

have invented certain new and useful Improvements in Speed-ChangingCam-Driving Mechanisms, of which the following is a specification.

The present invention relates to cam driving mechanism for varying thespeed and may for instance be used to advantage inconnection with screwmaking and turning lathes. Such an application is shown and described inmy copending application, filed 16 Nov. 28, 1922, Serial No. 603,871. lThe object of my invention is to provide an improved mechanism forimparting alternately a slow and fast movement to a rotating member.When applied to a screw machine one or several cams are mounted on anauxiliary cam shaft and this shaft is driven alternately by the main camshaft rotating at a constant slow speed and by a fast rotating driveshaft, whereby the con.- 2 pling of the auxiliary camshaft with bothdriving shafts is controlled in such a manner that the driven shaftcompletes each revolution in the same amount of time as is needed by themain cam shaft for one revo-' 3o lution.

In the drawings accompanying and form-- ing part of this specification-Figure 1 is a rear elevation of a screw making and turning lathe with myinvention applied thereto,

Figure 2 is an end elevation with the gear case cover removed partly insection,

Figure 3 is a front elevation of the speed changing mechanism,

Figure 4 is a sectional view of part of the vmechanism shown in Fig. 3,and

Figure 5 is a top view to Figure 3. Referring to the drawings in whichlike characters of reference indicate corresponding parts whereveroccurring, power is transmitted to the screw machine through a pulley 1which is connectedby a couplin to a drive shaft 2. The latter isjournals in bushin s' ofa gear case 3 and agear case cover 4. e movementis transmitted from the driving shaft 2 through gears 5, 6 and 3 thisapplication filed June 7, 8 to a main shaft 9 whiehdrive's' a mainspindle and a threading mechanism. Particular details of these drivingconnections a have not been shown as beingrimmaterial to this invent on.From the main shaft 9 movement is also transmitted through-spur gears 10and 11, bevel gears 12 and 13,

shaft 16. Mounted on this cam shaft are several cams of which 17 is acam, for actuating a turning tool carrier 19 while 18 .and, a worm drive14 and 15 to a cam represents a cam for controlling the movement of aform' tool carrier 20.

The driving shaft 2 rotates at a constant fast speed, while the main camshaft 16 rotates at a slow constant speed, which may be varied by usingdifferent gears in accordance with the time required for producing acertaii part. An auxiliary cam shaft 21 is mounted rotatably in bearingsof the gear case-3 and the cover 4.

To "accomplishthe desired object, that is to rotate the-cams mounted onthe auxiliary cam shaft slowly during the cutting operations andveryfast during the nonproductive period and yet complete eachrevolution synehronously with the main cam shaft, two gear 22 and 23 areprovided, of which gear 22 is driven by the slowly rotating cam shaft 16through a gear 24 while gear 23 is rotated by the fast running driyeshaft 2 through a gear 25, and the auxiliary cam shaft 21 is coupledalternately with these two gears 22 and 23. A clutch 26 disposed betweenthe gears 22 and 23 is mounted slidingly on but fixed rotatably to shaft21 by means of a pin 27 which is driven into shaft 21 and extendsthrough slots" cut into the clutch. Two notches spaced at 180 are cutinto one face of the clutch 26 and two corresponding noses 28 integralwith gear 22 fit therein, while clutch teeth 29 have been cut into theopposite face of the clutch mem ber 26 and mate with teeth out into thehub of the gear 23. The gear 22 is journaled with a hub in the bearing.30 of gear case 3, collar 31 holding it against axial movement.Similarly the gear 23 is located in the bearing 32 of the cover with acollar '33 preventing axial play. Thrust ball bearproximately hal thecover 4 and the gear 23 and a sleeve 34 in order to take up the pressureexerted upon the sleeve 34 by a nose 35 fastened to a. lever 36. Thislever 36 is pivoted to a hub in the gear case 3 and stands under theinfluencev of a spring 37. Two fork like ends of the lever 36 reach overand under the clutch 26 and carry two rollers 38. These; rollersactuated by the spring 37 bear against a rim on clutch 26, when the nose35 which is fastened to the lower arm of the fork drops into a recess 39cut into the face of the sleeve 34, and throw the clutch 26 into meshwith the gear 23. The sleeve is fastened by the pin 27 to the auxiliarycam shaft 21 and both rotate in unison with the clutch 26. When rotatingfurther'in the direction of the arrow after the nose.35 has dropped intothe recess 39 a gradual slope on the backside of this recess pushes thenose 35 and the lever 36 with the rollers 38 back to the originalposition. A spring 40 disposed around the shaft 21 tends now to throwthe clutch 26 out of mesh with the gear 23 and back into engagement withthe gear 22 but cannot effect t is movement until the notches in theclutch coincide with the two noses 28 on the gear 22, which occurs aftera relative movement of 180 between the clutch. 26 and the gear 22 hastaken place. The spring 37 of course must be considerably stiffer thanthe spring 40 in order to efiect the movements as described.

In order that the auxiliary cam shaft 21 may complete each revolution inthe same time as the main cam shaft 16 the gear 22,

in case two noses 28 have been provided, must rotate half as fast as thegear 24 or have double the number of teeth. In this b cam shaft 21rotatds apa revolution slow in engagement with the main cam shaft 16 andhalf a revolution fast in engagement with the drive shaft 2. Actually 1tmoves somecase the auxilia what more than 180 fast, because the slow-' 1running car 22 turns a certain distance d iiring the fast movement ofthe clutch 26. Supposing a different number of noses 28 have beenchosen, the ratio between the gears 24 and 22 and between the fast andthe slow movement of the shaft 21 must change correspondingly. Two camplates 41 and 42 for controlling the feeding of the material are formedintegral with a cam body 43, while a cam 44 for the radial movement ofthe out off tool is secured rigidly thereto.

7 The cam body 43 is mounted on a-fluted portion of the auxilia camshaft 21 between the bearings 30 ani l 45 of the ar-case 3. A slide 46is moved upwards the cam 41 and downwards by the cam 42, rollers 47 and48 being interposed.

A reciprocatln movement of the feed mechanism at rig t an Ice to themovement of the slide 46 is caused by an angulary ad- -myself to theexact in fixed relation by said justable guide 49 of U-shaped form, aroller of the feed mechanism fitting into this recess and transmittingthe movement.

The cams for controlling the various operations are divided into twogroups of which the one comprises the cams working continuously, forinstance cutting off and feeding of the bar of material and the othercontains those cams, which are provided for intermittent operations asturning, threading, forming and removing the completed part-to aslotting saw or a container. Of course this grouping of the differentcams may be varied accordin to the objects in View. By arranging all t ecams working only intermittingly on a cam shaft rotating with a constantslow speed it becomes possible to mount the few remaining parts on anauxiliary cam shaft, which may may be accelerated during possibleotherwise. In the machines actually built and successfully operated thetime consumed for the fast operation of the auxiliary cam shaft is onesixth of a second and yet the blow when engaging the auxiliary cam shaftwith thefast rotating shaft is hardlyperceptible.

Having now fully explained my invention I do not wish to be understoodas limiting details of construction modifications will occur asobviously mag in the art.

to a person skill at I claim is: 1. In combination a shaft rotating at aconstant slow speed,'a member rotating at a constant fast speed, asecond rotating memer in engagementduring each revolution alternatelywith said slow speed shaft and said fast rotating member and controllingmeans for causing said second rotating member to complete eachrevolution in the same time as said slow speed shaft.

2. In combination a shaft, a member rotating in fixed relation to saidshaft, engaging means on said member, a different member rotating at afast speed also engaging means a rotating part engaging alternately withsaid two members and controlling means for causing said rotating part tocomplete each revolution in the same time as said shaft.

3. In combination a shaft carrying cams,

a part turning'in fixed relation to said cam shaft, a drive shaft, adifferent part driven drive shaft, both means, another parts carryingengaging and a coupling shaft also carrying cams mounted. onsaid lattercam shaft for gengaging with both said parts and means for effectingalternate engagements.

4. In turning and screw cutting machines a cam shaft, agear rotating inrelation to said cam shaft and carrying two engaging means, a memberrotating at a fastspeed also carrying engagmg means, an auxihary camshaft carrying two engaging means mating with the engaging means on saidgear an other engaging means to couple with the engaging means carriedby the member rotating at a fast speed, and separate means foralternately effecting engagement with both said engaging means.

5. In turning and screw cutting machlnes a cam shaft, a gear driven byand rotating at half the speed of said cam shaft and carrying twoengaging means, another gear rotating at a fast speed carrying differentengaging means, an auxiliary cam shaft, a coupling member rotating withbut/sliding on said auxiliary cam shaft to engage alternately with saidtwo gears and means for effecting this alternate engagement.

6. In turning and screw cutting machines a drive shaft, a main camshaft, an auxiliary cam shaft, a coupling member driving said auxiliarycam shaft and rotating alternately in fixed relation to said main camshaft and said drive shaft and means rotating with said auxiliary camshaft for controlling the alternate engagement of said coupling member.

7. In turning and screw cutting machines a cam shaft, 2. drive shaft, anauxiliary cam shaft, a coupling member driving said auxiliary cam shaftand being driven alternately during each revolution by said cam shaft, acam for controlling these alternate engagements rotating with saidauxiliary cam shaft. and springs for effecting these alternatecouplings. Y

8. In turning and screw cutting machines a'cam shaft, a driving shaft,an auxiliary cam shaft, being alternately driven by said cam shaft anddriving shaft and completing each revolution in the same-time as themain cam shaft and cams turning with the auxiliary cam shaft forcontrolling the feed of the material through the, machine.

9. In turning and screw cutting machines a cam shaft, 2. driving shaft,an auxiliary said cam shaft and said drive shaft and completing eachrevolution in the same period of time as the main cam shaft, cams forcontrolling the feeding movement of the mate rial and the cut offoperation being mounted on said auxiliary cam shaft and other camsmounted on and turning with said main cam shaft for controllingdifferent operations necessary for completlng a part.

11. In turning and screw cutting machines a plurality of cams rotatingat a uniform speed and making one revolution for each part completed andother cams rotating alternately during each revolution at a slower and afaster speed than the first cams and completing also each revolution inthe same time as said first cams.

1-2. In turning and screw cutting machines a plurality of cams rotatingat a uniform "feeding mechanism and cut off means, both feedingmechanism and cut off means being controlled by the latter cams rotatingat a variable speed.

In testimony whereof I afiix my signature.

LORENZ KONRAD "BRAREN.

